Food used for canning must be canned within 12 hours
of harvesting. Most foods begin losing their vitamins immediately.
Choose food that is free of bruises, discoloration, and defects. The
quality of your canned product will only be as good as the food you have
chosen. Wash the food you have harvested. Prepare it as needed by
peeling, pitting, or slicing. Scald to remove skins from fruits and
vegetables when necessary.
Two methods are used when packing the jars for the
canning process:
-
Hot packing is when food is heated thoroughly
before it is packed into jars. It should be packed loosely, since
hot packed food does not shrink. This method naturally removes
air. When hot packed jars are put into the canner, water should be
boiling to avoid jar breakage.
-
Cold Packing is when raw food is placed into the
jars. It should be packed tightly since the food shrinks using this
method. When cold packed jars are placed into the canner, water
should be hot. Bring to a boil AFTER the jars are placed to avoid
glass breakage.
The space between the food and the lid is called
headspace. Proper headspace is required for the expansion of food and
for forming vacuums in cooled jars. For jams and jellies, 1/4/ in. is
required. For fruits and tomatoes, leave 1/2 in. For low-acid foods,
1-1 1/4 in. is needed.